Manufacture of commutators.



` A. E. DOMAN. MANUFACTURE 0F COM'MUTATORS. APPLICATION'HLED Dc.26'.i916.

Patented Oct. 22, 1918.

UNITED sTATEs PATENT oEiaIoE.

ALBERT E. DOMAN, OE ELBRIDGE, NEW YORK, AssIGNoR, BY MEsNE ASSIGNMENTS,TO DYNETO ELECTRIC CORPORATION, OE sYRACUsE, NEW YORK, A CORPORATION 0FNEW YORK.

MANUFACTURE OF COMMUTATORS.

To all whom t may concern:

Be it known that I, ALBERT E. DOMAN, a citizen of the United States ofAmerica, and resident of Elbridge, in the county of Onondaga, in theState of New York, havey which the bars or segments thereof are made. IThe primary object of the invention is to' reduce the expense of rawmaterials, as copper, and the cost of manufacture b forming the rawmaterials preferably in ong, cold drawn strips tapered laterally from acentral portion or formed with a double bevel so that the bars, withsuitable integral tangs,

may be punched from the strips with butslight waste of material, theangle or bevel of the strip being of such degree as to correspond with arequired angle when a predetermined 'number of bars or segments are tobe nested together to form a complete cylinder. y

Other objects and advantages will appear from the following descriptiontaken in connection with the accompanying drawings, in which* Figure lis a view of the blank of this invention from which the commutator barsor segments may be punched.

Fig. 2' is a top plan view ofthe blank, the shape of the bars and themethod of punchin` being indicated.

ig. 3 is a view of a complete bar or seg ment.

Fig. 4 is a cross section of a commutator as constructed from suchsegments.

The invention, as shown, comprises the blank -1- which inay preferablybe a relatively long, cold drawn strip of suitable material, as copper,having a central substan-- tially plane horizontal portion -2- with sideportions -3- and -4- tapered or beveled in opposite directionstherefrom. Both sides of the blank are symmetricalV and of'the sameconformation. f

The side portions -3- and -4- are disposed at the same angle relativelyto the portion -1- and are of equal width, the angle of disposition ofthe outwardly converging Specification of Letters Patent.

Application illed December 26, 1916. Serial No. 138,971.

Patented Oct. 22, 1918.

portion -3 or the outwardly converging portion -4- being of such adegree as is required in the manufacture of a complete cylinder from apredetermined number of similarly shaped nested bars or segments. With acommutator constructed of thirtythree bars or segments as hereillustrated, the angle of disposition of the outwardly converging sideportions -4- or the ou'twardly converging side portions -3- isapproximately 10, 51', 32, the angle of dispositionof each beveledportion -4- or each beveled portion 3- and the central the angle lastdescribed. The angular disposition will, of course, vary in accordancewith the number of segments to be used in forming a complete cylinder.

The strip -1- is of a width equal to the complete width of thecommutator bar 5-- including the tang -G for electrical con- -7- of thecommutator bar adapted to form the cylindrical portion of thecommutator.

From the strip -lw commutator bars -5- can be punched or cut with aminimum Waste of material and with a minimum cost of production in themanner shown in Fig. 2. The bar is punched along lines 8, 9 and 10, theline 8 extending from one side of the bar to the central portion of thebar, said line being spaced from the adjacent end of the strip -1- adistance equal to the desired wldth of tang The line 9 extends from theinner terminationV of line 8 longitudinally and centrally of the strip.

'shaped member 1l-'adapted to receive suitable, usual and well knownmeans, as ring members, for holding the segments in nested position inthe completed commutator. These portions -13- and 14- which are cut outto form the wedge-shaped member -11- are Athe only waste material inconstructing the commutator bars.

In order to form the second commutator ,.'portio'n fbeing approximatelyone-half ,nections and is twice theA width of the body equal in wid-thto the radial length of a com' mutator bar and equal in length to thecomplete Width of a commutator bar plus the width of one tang.

The bars, as shown, may be mounted upon a suitable sleeve or core l5-and may be held in assembled position upon the sleeve in any suitableand usual manner.

Although I have shown and described one particular construction andexact method as constituting a preferred embodiment of this invention,1t will be apparent that changes and alterations may be made in theexact form of the commutatorvbar and the exact method of punching thesame Without departing from the spirit ot this invention as set forth inthe appended claims.

Whatl claim isz- 1. The method of manufacturing commutator barsconsisting in forming suitable material into a relatively thin Widestrip tapering from a central portion toward opposite edges, cutting thebar at substantial right angles to its length from a .predetermined edgeto substantially the central portion of the bar and along a line locatedat a distance from the end of the bar substantially equal to the Widthof the tang of the commutator bar to be produced, cutting the barlongitudinally along its central portion a distance equal to the Widthof the commutator bar to be produced less the width of the said tang,cutting the bar at right angles to its length from the termination ofthe said central longitudinal cut Ito the ed e opposite thepredetermined edge first re. erred' to, cuttin the bar at right anglesto its length an throughout Its entlre Wldth at a distance from thelast-named cut substanfirst referred to, cutting the bar at rig tiallyequal to the width of the tang of the commutator bar to be produced,removing spaced wedge-shaped portions from the opposite edges of saidstrip at corners adjacent the respective cuts described to form keystoneshaped parts at the opposite edges, said parts tapering in thicknesstoward their longitudinally Wider portions.

2. The method of manufacturing commutator bars consisting in formingsuitable material into a relatively thin wide strip havin .a centrallane portion with opposite si es substantia ly parallel and oppositeside portions having tieir opposite walls convergin outwardly, cuttingthe bar at substantia ly right angles to its length from a predeterminededge to substantially the central portion of the bar and along a linelocated at a distance from the end of the bar substantially equal to theWidth of the tang of the commutator bar to be produced, cut- `ting thebar longitudinally along its central portion a distance equal to thewidth of the commutator bar to be produced less thc width of the saidtang, cutting the bar at right anglesto its length from the terminationof the said centrallongitudinal cut to the edge opposite thepredetermined edge it angles to its length and throughout its cntirewidth at a distance from the last named cut substantially equal to theWidth of the.

tang of the commutator bar to be produced, removing Ispaced wedge-shapedportions from the opposite edges of said strip at corners adjacent therespective vcuts dcscribed to form keystone shaped parts at thelopposite ed es, said parts tapering in thickness towar theirlongitudinally Wider portions.

In witness whereof I have hereunto se: my hand this 20th day ofDecember, 1916.

ALBERT E. DOMAN.

Witnesses:

WILLIAM Mm'rzaorH, AUSTIN M. CATELY.

